Mold packages are used to encapsulate electronic devices, including semiconductor chips, to protect from undesirable environmental conditions. Such undesirable conditions include light, heat, humidity, dust, and physical shock. In particular, mold packages are widely used in sensor applications and application specific integrated circuit (ASIC) and integrated circuit (IC) packaging since the mold packages provide a low cost package suited for high volume applications. Most packaging includes the use of a black plastic material, typically including epoxy molding compounds. While many electronic components are completely covered by the mold, except for the contacts extending from the component itself, sensors of many types require a mold package that does not completely cover the device.
Many sensors directly interact with the environment being sensed and therefore require direct access to the sensed environment. Such sensors include gas-sensors, pressure sensors, bio-sensors, finger-print sensors, and humidity sensors. For these types of sensors, an “exposed-die package” is used which provides a mold which does not cover a predetermined area of the sensor which includes the structure of the sensor providing the sensing function. The drawback of such packages, however, is that since the entire device is not covered by the mold, there is a high probability of mold-delamination at an interface of the mold and the sensor device. Where devices are formed of silicon, the mold-silicon interface (or whatever top-most material is used on the sensor) near the exposed sensor-area can delaminate from the silicon.
Consequently, there is a need for a mold package that reduces or substantially prevents the occurrence of delamination between the mold and the sensor.